Automatic toolchain upgrade to nightly-2026-01-06

[github-actions]

Update Rust toolchain from nightly-2026-01-05 to nightly-2026-01-06 without any other source changes.

[github-actions]

This is an automatically generated pull request. If any of the CI checks fail,
manual intervention is required. In such a case, review the changes at
https://github.com/rust-lang/rust from
rust-lang/rust@e29fcf4 up to
rust-lang/rust@4fa80a5. The log
for this commit range is:

https://github.com/rust-lang/rust/commit/4fa80a5e73 Auto merge of #150700 - Kobzol:rollup-02y1lh9, r=Kobzol

rust-lang/rust@bd33b83cfd Auto merge of #149784 - fereidani:retain_mut, r=joboet
rust-lang/rust@469a26439c Rollup merge of #150697 - hkBst:relate-3, r=Kivooeo
rust-lang/rust@5bcdc7c131 Rollup merge of #150384 - reddevilmidzy:t14, r=Kivooeo
rust-lang/rust@b198dffd98 Rollup merge of #149790 - JonathanBrouwer:attr-path-perf, r=jdonszelmann
rust-lang/rust@3d6a2c5ae1 relate.rs: tiny cleanup: eliminate temp vars 2
rust-lang/rust@b7bcaa5c71 Auto merge of #143741 - connortsui20:oneshot, r=joboet
rust-lang/rust@9e8a0c5164 Auto merge of #150692 - jhpratt:rollup-kfi61p5, r=jhpratt
rust-lang/rust@d788ec5e9a Rollup merge of #150684 - moturus:main, r=jhpratt
rust-lang/rust@a1221deafd Rollup merge of #150547 - Ayush1325:uefi-rename, r=jhpratt
rust-lang/rust@fe5a1d7332 Rollup merge of #146863 - matwatson:core-cell-improve-doc, r=tgross35
rust-lang/rust@0d162b25ed Auto merge of #150535 - Kobzol:rename-ci-gcc, r=jieyouxu
rust-lang/rust@6885bdf1af Auto merge of #150603 - Kivooeo:tuple-struct, r=BoxyUwU
rust-lang/rust@3f1dd92cc7 Motor OS: fix compile error
rust-lang/rust@b481ecd8b5 add oneshot tests
rust-lang/rust@9ba5b5e7f7 add experimental oneshot channel
rust-lang/rust@451b7b6c77 Auto merge of #150682 - matthiaskrgr:rollup-jrkhivl, r=matthiaskrgr